Honeycomb ceramics having a high thermal shock resistance and low permeability have been proposed for use as rotary heat exchangers (regenerators) for gas turbines and other heat engines, where leakage of hot gas must be minimized. A low-CTE material having low porosity and a very fine mean pore size would also exhibit an improved strength, which could be advantageous as an automotive catalytic converter substrate having very thin walls and a high cell density (cells/unit area) designed for reduced back pressure and increased geometrical surface area. A number of approaches to produce a low-porosity cordierite body have been proposed. None have achieved the desired combination of low CTE and very low porosity, and many require the use of sintering additives that can reduce the refractoriness or the stable firing range of the ceramic body.
The present invention fills the need for a low expansion low porosity cordierite body.